(a) Scope and purpose. An engineering design report that describes existing conditions, problems, and the proposed solution is required for each project.
(b) Sewerage systems. The engineering design report shall include: - (i) A description of the service area including scaled vicinity plan map(s) of the project with regard to adjacent and proposed development, elevations, and topographic features.
- (ii) Current and projected average, maximum day and peak flows for the design of the project, per capita design flows, extraneous flows, and industrial and/or commercial waste flows.
- (iii) Downstream impact on existing sewers, lift stations and treatment facilities. This information shall include existing population, waste loads, existing flows and capacity of downstream facilities.
- (iv) A letter of acceptance from the municipality, sewer district, or owner of any affected downstream sewerage, treatment or disposal facilities.
(c) Treatment works and disposal systems. The engineering design report shall include: - (i) A description of the facility site and location, including scaled site plan and:
- (A) Present and projected facility property.
- (B) Flood protection indicating predicted elevation of 25- and 100-year flood stages.
- (C) Present and proposed access.
- (D) Distances from current habitation.
- (E) Prevailing wind direction.
- (F) Fencing and/or security.
- (G) Topographic features and contours with indicated datum.
- (H) Soil and subsurface geological characteristics. Location of soil borings, rock elevations and groundwater elevations shall be indicated. Provide a soils investigation report of the proposed site.
- (ii) A detailed description of the service area for the project including scaled plan showing land use and boundaries.
- (iii) A detailed description of the disposal technique for effluent and solids. For lagoons, indicate whether the discharge is continuous, seasonal, or nondischarging.
- (iv) Effluent water quality considerations for design of the facility shall be described to include:
- (A) Surface discharge. An application shall be submitted to the Water Quality Division for a National Pollution Discharge Elimination System Permit.
- (B) Groundwater protection. Pursuant to Chapter 8 of the Water Quality rules.
- (v) Design conditions shall be described to include:
- (A) Proposed effluent standards.
- (C) Existing and projected flows and flow variations.
- (D) Shock loads, with cause and frequency.
- (E) Existing and projected wastewater characteristics including BOD, suspended solids, and pH.
- (F) Existing and projected flow, loads and characteristics of industrial wastes and toxic Materials.
- (G) Existing or proposed quantity and frequency of septage discharges.
- (H) Climate conditions at existing or proposed treatment facility site.
- (I) Existing or proposed water supply.
- (K) Odor control features.
- (L) Complete description of existing facilities.
- (vi) Specific requirements of any pertinent approved Water Quality Management Plan shall be included.
020-11 Wyo. Code R. § 11-6